三维金属氧化物-金属复合光子晶体结构光阳极构筑及协同增强光解水性能研究

Solar light driven photoelectrochemical water splitting is a promising way to address the energy crisis and environmental pollution issues simultaneously. Current photoelectrodes for photoelectrochemical water splitting has disadvantages in low efficiency and fail to take account of the three processes of photons absorption, charge transport and separation simultaneously. As such，it is very important to develop semiconductor photoanodes with wide-spectrum light response、high charge and transport separation efficiency simultaneously in a single electrode design. In this proposal, we plan to design and fabricate three-dimensional nanostructured visible-light responsive metal oxides semiconductor-plasmonic metal composites photonic crystals photoanodes for photoelectrochemical water splitting by colloid spheres templates routes combined with atomic layer deposition technique and so on. In this electrode configuration, the transparent conductive electrodes photonic crystals are used as conductive skeletons to support the semiconductor light absorber layers（Fe2O3，BiVO4 etc）and plasmonic metal particles, it is expected to improve the light harvesting efficiency, charge transport and separation efficiency in a single electrode simultaneously by the special transparent conductive current collector electrode design, surface plasmons resonance enhancement by plasmonic metal particles and slow photons effect induced by photonic crystals, as a result of fabrication of water splitting materials and devices with high energy conversion efficiency. Further investigations on the underlying physical mechanism of water splitting by a series of spectroscopy characterization techniques such as electrochemical impedance spectroscopy, time-resolved ultra-fast light absorption spectra and theory simulation would reveal the key factors on the device efficiency, as a result, providing some guidances for the future design and preparation of photoelectrochemical water splitting materials and devices with high efficiency.

太阳能光电化学分解水制氢技术是同时解决能源危机和环境污染问题的有效途径之一。目前光电催化分解水光电极仍存在效率低，无法同时兼顾光子吸收、载流子传输、分离三个过程等问题，开发具有宽光谱响应、高效载流子传输与分离效率的半导体光阳极具有重要意义。本项目计划通过胶体模板法结合原子层沉积技术等手段制备三维可见光响应金属氧化物-金属颗粒复合光子晶体结构光阳极应用于光电催化水分解，该结构设计利用透明导电材料作为骨架负载半导体（氧化铁，钒酸铋等）吸光层和金属颗粒，期待利用透明导电集流体结构设计协同金属表面等离子体共振效应以及光子晶体“慢光子效应”等途径同时提升光阳极光俘获效率、载流子传输与分离效率，从而提升光解水效率，进一步通过一系列光谱表征如电化学阻抗谱、超快吸收光谱以及理论模拟手段从实验和理论两方面揭示影响光解水效率的物理机制和关键因素，为将来制备高效率光电催化分解水制氢材料与器件提供理论指导。

随着全球能源需求的持续增长和对温室气体减排及环境污染问题的关注，发展清洁、可再生新能源已经成为世界各国的重要战略。太阳能光电化学分解水制氢技术是同时解决能源危机和环境污染问题的有效途径之一。当前光解水效率仍然较低，过去很多研究仍然集中在单一途径改善半导体光电极光子吸收、载流子传输与分离某一方面性能，如何同时实现光电极宽光谱响应、高效载流子传输与分离效率具有一定挑战。在国家自然科学基金（51772213）资助下，本项目利用胶体模板法结合原子层沉积技术、电化学沉积等手段制备了系列三维有序金属氧化物复合光子晶体结构光阳极应用光电催化水分解，取得的如下主要研究成果：1. 发展了胶体微球模板结合原子层沉积等手段制备三维周期有序金属氧化物复合光子晶体结构光阳极新方法，如TiO2/WO3/BiVO4仿生“网粒体”、 SnO2/TiO2/BiVO4分级结构、 TiO2/Fe2O3海胆状结构、FTO/Fe2O3反蛋白复合光子晶体等。2. 揭示了影响光解水效率的主要因素以及三维有序光子结构、金属表面等离激元共振调控光电极光吸收效率、半导体异质结设计改善光电极载流子传输与分离效率、表/界面修饰调控载流子分离效率和表面反应动力学的物理机制，大幅提升了Fe2O3基和BiVO4基半导体光阳极光电催化分解水性能, 为设计制备高效率光电催化分解水制氢材料与器件提供了指导思路。3. 在半导体光解水助催化剂研究方面，设计制备了系列自支撑结构电催化析氢/析氧催化剂，如CoP、NiFeP、W2C等，揭示了催化剂电催化析氢、析氧反应物理机制。4. 发表SCI论文25篇，培养博士研究生3名，硕士研究生5名。